Tesla Roadster

Tesla Motors has some good news for fans of the American maker of electric cars. The Model S -- its first reasonably priced vehicle -- may hit the streets as early as June. Will this be the vehicle that jump starts electric car sales?

Bad news for GM: The Chevy Volt still isn't selling the way the automaker hoped it would, so it's temporarily halting production of the battery-powered hybrids for five weeks. Worse news for GM: Shutdowns like this only make the Volt a harder sell.

The electric car has arrived, but odds are that there isn't one in your driveway. Several factors have gotten in the way of the eco-friendly automotive revolution, but at least now we can ask conspiracy theorists -- who argue that oil companies and the government are blocking plug-in cars from the road -- to leave the room and take their tinfoil hats with them. The electric car is here; drivers simply don't want them yet.

If you think a stock will fall, you can still profit on it -- by shorting it: Just sell shares you've "borrowed," then buy them later, ideally at a lower price. But it can be risky. Here are 5 companies you might be tempted to bet that way against -- and shouldn't.

Tesla Motors, which went public with much fanfare last June, nearly tripled its losses for 2010 as it invested heavily to engineer and get ready for producing the Model S, its second offering and the first that targets a broader consumer market.

The automaker has licensed technology from the Energy Department's Argonne National Laboratory that will boost the performance of lithium-ion battery cells. The next-generation power packs will be made at a new plant in Michigan by Korea's LG Chem.